Take a look at these:
https://pubs.ext.vt.edu/426/426-617/426-617_pdf.pdfhttps://www.unce.unr.edu/publications/f ... fs0732.pdfFrom what I gathered, it isn't generally recommended due to possible contamination of your crop with harmful microorganisms if your leech field isn't operating properly. However, it sounds possible as long as you put a good layer of mulch down around your plants to keep any edible parts from touching the ground or getting rain splatter. You also would need to be 100% sure that your leech field is operating correctly, and monitor it continuously. The main concern is that if raw septic fluid made it up to the surface, and you ate produce that came in contact with it, you could become seriously ill.